Computer Science Review 37 (2020) 100272 Contents lists available at ScienceDirect Computer Science Review journal homepage: www.elsevier.com/locate/cosrev Review Article Indoor environment propagation review H. Obeidat a,∗ , A. Alabdullah b , E. Elkhazmi c , W. Suhaib d , O. Obeidat e , M. Alkhambashi f , M. Mosleh g , N. Ali h , Y. Dama i , Z. Abidin j , R. Abd-Alhameed b , P. Excell k a Faculty of Engineering, Jerash University, Jordan b Faculty of Engineering and Informatics, University of Bradford, Bradford, UK c Engineering and Information Technology Research Centre, Bani Walid, Libya d Faculty of Engineering, Omar Al-Mukhtar University, Libya e College of Engineering, Wayne State University, Detroit, USA f Women College, Oman g Middle Technical University, Baghdad, Iraq h Khalifa University, United Arab Emirates i An Najah University, Palestine j Universiti Tun Hussein Onn, Malaysia k Wrexham Glyndwr University, Wrexham, UK article info Article history: Received 4 January 2020 Received in revised form 28 April 2020 Accepted 25 May 2020 Available online xxxx Keywords: Constitutive electrical parameter Dominant direct path Indoor propagation models Propagation through Building models MIMO Radiofrequency propagation Ray tracing abstract A survey of indoor propagation characteristics is presented, including different models for path loss, shadowing and fast fading mechanisms, different channel parameters including signal strength, power delay, coherence bandwidth, Doppler spread and angle of arrival. The concepts of MIMO channels are also covered. The study also explores many types of deterministic channel modelling, such as Finite Difference Time Domain, Finite Integration Method, Ray tracing and the Dominant path model. Electromagnetic properties of building materials, including frequency dependence, are also investigated and several models for propagation through buildings are reviewed. © 2020 Elsevier Inc. All rights reserved. Contents 1. Introduction......................................................................................................................................................................................................................... 2 2. Indoor and outdoor propagation comparison ................................................................................................................................................................ 2 3. Frequency allocation ......................................................................................................................................................................................................... 2 4. Modelling indoor channels .............................................................................................................................................................................................. 3 4.1. Stochastic models (site general models)............................................................................................................................................................. 3 4.1.1. Path loss models .................................................................................................................................................................................... 3 4.1.2. Shadowing and multipath ..................................................................................................................................................................... 7 4.2. Deterministic models (site specific models)....................................................................................................................................................... 9 4.2.1. Ray tracing ............................................................................................................................................................................................. 10 4.2.2. Finite Difference Time Domain (FDTD) .............................................................................................................................................. 10 4.2.3. Dominant path model .......................................................................................................................................................................... 11 4.2.4. Finite Integration Technique (FIT) ...................................................................................................................................................... 12 5. Effects of building materials ............................................................................................................................................................................................ 13 6. Propagation through buildings ........................................................................................................................................................................................ 15 6.1. Path loss exponent model with correction factors .......................................................................................................................................... 15 6.2. COST231 building penetration studies ............................................................................................................................................................... 15 6.3. Building penetration loss and extensions to the COST231 model ................................................................................................................. 16 7. Conclusions ........................................................................................................................................................................................................................ 18 ∗ Corresponding author. E-mail address: h.obeidat@jpu.edu.jo (H. Obeidat). https://doi.org/10.1016/j.cosrev.2020.100272 1574-0137/© 2020 Elsevier Inc. All rights reserved.